@hilde45 , back to the subject of phase, isn’t the goal to have sound from your speakers arrive at your ears at precisely the same time as the sound from your subs? And if the subs are directly beside your speakers (which is similar to the case of speakers that include powered subs), would the timing for sound from your speakers and subs to travel to your ears not be identical? I’m trying to understand the rationale as to why having the drivers of the subs be out of sync with my main speakers might be beneficial - I can understand in the scenario of when your sub is significantly further away from your speaker.
Finally, having your subs directly next to your speakers and being slightly out of phase from your speakers, wouldn’t the significant vibrations from the subs adversely affect the performance of your main speaker drivers, by having a slightly deleterious effect on each other? When people question how powered subs can be embedded in speakers without having a negative impact, I’ve always heard the argument that it’s because the vibrations are perfectly in sync and are therefore working together. Is it possible that having the crossover set too high amplifies the lower frequencies too much causing the boominess, and by having the phase set slightly apart, your speaker drivers and sub drivers are very slightly taming the bass response by slightly cancelling each other out?
I have no experience in this area or with subs in general, so I’m just trying to understand. Or is it one of those audiophile things that don’t make any sense, but it helps? (like for example I recently learned that 2m USB cords are vastly superior to 1m cords, when I tested 0.75m, 1m, and 2m versions of Audioquest Diamond and Nordost Valhalla 2 USB cords - makes NO sense but wow is there ever a difference!).